RDMA/umem: Fix missing mmap_sem in get umem ODP call

Add mmap_sem lock around VMA inspection in ib_umem_odp_get().

Fixes: 0008b84ea9af ('IB/umem: Add support to huge ODP')
Signed-off-by: Artemy Kovalyov <artemyko@mellanox.com>
Reviewed-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c
index 0780b1afefa9d996c870e6982bfc9c5f9b13fb2a..8c4ec564e49583f6d05eab8df5e57e4378582f08 100644 (file)
--- a/drivers/infiniband/core/umem_odp.c
+++ b/drivers/infiniband/core/umem_odp.c
@@ -321,11 +321,15 @@ int ib_umem_odp_get(struct ib_ucontext *context, struct ib_umem *umem,
                struct vm_area_struct *vma;
                struct hstate *h;
 
+               down_read(&mm->mmap_sem);
                vma = find_vma(mm, ib_umem_start(umem));
-               if (!vma || !is_vm_hugetlb_page(vma))
+               if (!vma || !is_vm_hugetlb_page(vma)) {
+                       up_read(&mm->mmap_sem);
                        return -EINVAL;
+               }
                h = hstate_vma(vma);
                umem->page_shift = huge_page_shift(h);
+               up_read(&mm->mmap_sem);
                umem->hugetlb = 1;
        } else {
                umem->hugetlb = 0;